Suspended Matter by Filtration

Easy method: Take a known quantity of your food (e.g. 10ml of orange juice).

Find out the mass of a piece of filter paper and of the orange juice.

Pass the orange juice through a standard filter paper in a funnel.

Allow the stuff on the filter paper to dry out, then take the mass of the filter paper with the filtered suspended matter on it. Subtract the mass of the filter paper from this mass.

This gives you the mass of the juice that was 'suspended matter'. Slightly more difficult, but much faster:

As above, put pass the juice through a Buchner Funnel under pressure to fully remove all water from the sample and pass the juice through the filter much more quickly.

The filter paper can now be weighed without the need to wait for water to evaporate.